Objective: To evaluate the efficacy of a new transdermal nicotine system for smoking cessation.
Design: Two 6-week, randomized, double-blind, placebo-controlled, parallel group trials were conducted. Successful abstainers from both trials enrolled in a third trial for blinded downtitration from medications (6 weeks) and subsequent off-drug follow-up (12 weeks).
Setting: Nine outpatient clinics specializing in the treatment of smoking cessation.
Patients: Healthy volunteers who smoked one or more packs of cigarettes daily and wanted to participate in a smoking cessation program.
Intervention: Patients were randomly assigned to a transdermal nicotine system delivering nicotine at rates of 21, 14, or 7 mg (in trial 1 only) over 24 hours or to placebo. Group counseling sessions were provided to all participants.
Main outcome measure: Rates of continuous smoking abstinence were determined during 6 weeks of full-dose treatment, a 6-week weaning period (through week 12), and a 3-month follow-up receiving no therapy (through week 24). Abstinence was defined by patient diary reports of no smoking during the designated periods, confirmed by expired-breath carbon monoxide levels of 8 ppm or lower.
Results: The centers enrolled 935 patients. Cessation rates during the last 4 weeks of the two 6-week trials (pooled data) were 61%, 48%, and 27% for 21- and 14-mg transdermal nicotine and placebo, respectively (P less than or equal to .001 for each active treatment vs placebo). Six-month abstinence rates for 21-mg transdermal nicotine and placebo were 26% and 12%, respectively (P less than or equal to .001). All transdermal nicotine doses significantly decreased the severity of nicotine withdrawal symptoms and significantly reduced cigarette use by patients who did not stop smoking. Compliance was excellent, and no serious systemic adverse effects were reported.
Conclusions: Transdermal nicotine systems show considerable promise as an aid to smoking cessation.